[U-Boot] [PATCH v3 2/3] MX31: Introduce get_reset_cause()

[Fabio Estevam <festevam@gmail.com>]

Introduce get_reset_cause() function to indicate the source of the reset.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
---
 arch/arm/cpu/arm1136/mx31/generic.c       |   26 ++++++++++++++++++++++++++
 arch/arm/include/asm/arch-mx31/imx-regs.h |    2 ++
 2 files changed, 28 insertions(+), 0 deletions(-)

diff --git a/arch/arm/cpu/arm1136/mx31/generic.c b/arch/arm/cpu/arm1136/mx31/generic.c
index 9b7a7a2..ea452a9 100644
--- a/arch/arm/cpu/arm1136/mx31/generic.c
+++ b/arch/arm/cpu/arm1136/mx31/generic.c
@@ -132,6 +132,32 @@ char *get_cpu_rev(void)
 		return "unknown";
 }
 
+char *get_reset_cause(void)
+{
+	/* read SRS register from CCM module */
+	struct clock_control_regs *ccm =
+		(struct clock_control_regs *)CCM_BASE;
+
+	u32 cause = readl(&ccm->rcsr) & 0x07;
+
+	switch (cause) {
+	case 0x0000:
+		return "POR";
+		break;
+	case 0x0001:
+		return "RST";
+		break;
+	case 0x0002:
+		return "WDOG";
+		break;
+	case 0x0006:
+		return "JTAG";
+		break;
+	default:
+		return "unknown reset";
+	}
+}
+
 #if defined(CONFIG_DISPLAY_CPUINFO)
 int print_cpuinfo (void)
 {
diff --git a/arch/arm/include/asm/arch-mx31/imx-regs.h b/arch/arm/include/asm/arch-mx31/imx-regs.h
index 74444f2..2b0881d 100644
--- a/arch/arm/include/asm/arch-mx31/imx-regs.h
+++ b/arch/arm/include/asm/arch-mx31/imx-regs.h
@@ -27,6 +27,8 @@
 #if !(defined(__KERNEL_STRICT_NAMES) || defined(__ASSEMBLY__))
 #include <asm/types.h>
 
+extern char *get_reset_cause(void);
+
 /* Clock control module registers */
 struct clock_control_regs {
 	u32 ccmr;
-- 
1.6.0.4